Die-casting machine



March 13, 1928. I 1,662,750

A. KAUFMANN DIE CASTING MACHINE Filed July 1'7, 1926 4 Sheets-Sheet 1 fll aufrnann March 13, 1928.

A. KAUFMANN DIE CASTING MACHINE Filed July 17. 1926 4 Sheets-Sheet 2 March 13, 1928.

A. KAUFMANN DIE CASTING MACHINE Filed July 1'7, 1926 4 Sheets-Sheet, 3

5 A au'fm a. H 71 In wen-hr flyfy March 13, 1928. 1,662,750

- A. KAUFMAN N DIE CASTING MACHINE 4 Sheets-Sheet 4 au [Mann mvenf-a Patented Mar. 13,

UNITED STATES A 1,662,750 PATENT OFFICE.

ALBERT KAUFMANN, OF BERLIN, GERMANY.

DIE-CASTING Application filed July 17, 1926, Serial No. l28, l57, and in Germanyjugust 3, 1985.

My invention relates to die-casting ma- I chines and it is an object of my invention tionary.

to improve machines of this type in which a fluid under pressure, generally air, is employed for displacing the die with regard to the injection nozzle and for opening and closing the die. Separate cylinders were provided for displacing and for controlling the die, and in the machines of the usual type the die control cylinder was arranged on the frame by which the die was displaced and this required a very rugged frame and a corresponding power input for displacing it.

In my invention, I overcome this draw back of the existing machines by combining the two cylinders into a single unit which is carried on the frame of the machine, the die control cylinder for closing and openin the die constituting the hollow piston 0 the frame control cylinder, the latter being sta- By this novel combination of the two 0 linders into a single unit not only the ie and the frame are moved in exactly parallel relation but it is also possible to provide automatic, positive and reliable means for regulating the operation of, the machine so that the frame can only be advanced toward the injection nozzle after the die hasbeen completely closed, and air can only be ad mitted to the injection nozzle when the die is in proper position with respect to said nozzle.

In the drawings accompanying this specification a die-casting machine embodying my invention is illustrated by way of example.

F igs. 1, 2 and 3 are plan views, partly in section, showing somewhat diagrammaticall chirib,

Figs. 4, 5, 6 and 7 are enlarged end elevational details showing various positions of the valves controlling the two cylinders of the unit,

Figs 8 and 9 are enlarged elevational details showing two positions of the s stem of toggle levers by which the supply 0 fluid under pressure to the injection nozzle is locked against untimely operation, this being effected by electrical means,

Figs 10, 11 12 and 13 are enlarged fragmentary details partly in section showing various positions of the cylinder control valves in combination with mechanical means for regulating the operation, and

three phases of operation of the ma-- Figs. 14 and 15 are enlarged elevational details showing two positions of mechanical means for preventing untimely operation of the fluid supply to the injection nozzle.

I will now proceed to describe my novel machine and its operation, it being understood that notwithstanding the fact that the fluid under pressure will be referred to as air, any other fluid may be employed.

Referring to the drawings,"and first to Figs. 1, 2 and 3, 1 is a reservoir containing molten metal, 2 is its injection nozzle, 3 is a pipe for supplying compressed'air to the reservoir, 4 is a control valve in the pipe 3, 5 is the core of an electromagnet coil' or a solenoid 6 which core is provided with means not shownfor causing it to enter a notch 4 in the body of the valve unless attracted by its coil, 7 is a source of ener and 8 is a contact in the circuit 7 of the coil 6.

The means for controlling the contact 8 will be described below.

The frame of the machine is not shown. A die frame 9 is adapted to be dis laced on the frame. The front part 10 of which is adapted to beconnected with the nozzle 2 is secured in the frame 9 and its rear part 11 is adapted to slide in the frame under the control of two pairs of toggle levers 12, 12' which are hinged to the rear part 11 at 12" and to the rear stay of the frame 9 at 13. 14 are levers linked to the pivots connecting the toggle levers at one end and to a cross head 15 at the other, 16 is a piston rod on which the cross head is secured, 17 is a piston on said rod, and 31 is its integral tail rod which extends through the rear cover 32 of a cylinder 19. The piston 17 is the die control piston and 18 is its cylinder which constitutes the hollow piston of the frame control cylinder 19 which i's'secured to the frame of the machine, and 18' is the tubular piston rod of this frame control cylinder which rod is adapted to slide on the solid piston rod 1601? the die control cylinder and is secured to the rear stay of the frame at its outer end.

22 and 36 are four-way valves controlling the supply of air to the cylinders 18 and 19. 2.3 is an air pipe and 23 and 23" are branch pipes connecting this pipe to the cases of the valves 22' and 36, respectively.

The body 25 of the valve 22 is provided with two passages 26 and 27. 20 is a pipe connecting the rear chamber K of the frame the die control cylinder 19 with a pipe 20' of the being coil, 54' is a source of electric ener valve case 22, and 21- is a pipe connecting the front chamber K of the cylinder with a pipe 21' of the valve case 22. 24 1s a pipe connecting the valve case22 with atmosphere. 28 IS a lever on the body. of the valve 22, and29 is an elongated open eye at the end of the lever.

The other valve36 comprises a valve body 38 with two passages 39 and '40. 33 and 35' are pipes on the case of the valve and, 33 and 35 are flexible pipes connecting thepipes 33' and 35 with passages and 34in tie tail rod 31. The passage 30 opens into the chamber K of the hollow piston 18 at the rear of the die control pistonl'l "and the. passage 34 o ens into the chamber K atthe front of t e piston 17. 37 is a pipe connecting'the valve, case with atmosphere. 41 is a lever having an open elongated eye 42 and secured on the body 38 of the valve 36.

43 is a horizontal control shaft carried in the frame intermediate the valves 22 and 36, 44 is' a handle secured on the square front end of the shaft 43, and 46, 47 is a bell crank lever ke ed on the shaft 43 and rovided with re ers 48 and 49 which are a apted to engage the slotted eyes of thelevers 41 and 28, respectively. I

50 is a cam also secured on the shaft 43 and adapted to cooperate with the core 52 of an' electromagnet or solenoid coil 53 which tends to enter a recess 51 of the cam 50 unless attracted by .its coil. 54 is the circuit of the and 55 is a contact, both in the circuit 54,t e contact normally open and adapted to be closed by t e toggle levers 12 when such levers are straightened out as shown in Figs. 2 and 3. 56, 57 are two more pairs of toggle levers which are pivoted to the rear stay of the frame 9 at one end and to the machine frame at the other, and, 58 are eccentrics on the shaft 43 which move the toggle levers out of their straightened position. The pair of toggle levers at the left is adapted to cooperate with the contact 8 of the circuit 7, the lever 57 closing the contact when the levers are straight as shown in Fig. 9.

The operation of my machine is as follows: In the initial positlon shown in Fig. 1, the frame 9 is at a predetermined distance from the injection nozzle 2, the toggle levers 12, 12 and the to gle levers 56, 57 are at an angle to each ot er, the die is open and the circuits 7 and 54 are broken at "their respective contacts 8 and 55. The core 5 of the coil 6 locks the valve 4 against rotation by entering the notch 4 and the core 52 of the coil 53 is in the recess 51 of the'cam' 50. The handle 44;is in the position shown in Fig. 4 in which the roller 48 at the arm 46 is about to enter the open eye'42 of the lever 41. Air from 23 and 23 enters the chamber K of the die control cylinder 18 via 39, 35 and 34, holding the piston 17 in its rear end position in. the hollow piston 18. At the same time, air is supplie to the chamber K of the-cylinder 19.via 23, 23', 26, 21" and 21 so that the piston 18 is also held in its rear end position in the cylinder 19. The chamber K.

and K are connected to atmosphere via 20, 20127, 24 and 30, 33, and 37, respectlvely.

Too rate the machine, the handle 44 1s turnedm the direction of the arrow until it assumes ,the' :position shown in Fig. 5 in which furtheroperation of the handle is preventedbytheend of the recess striking the core .52." In this position the amt 46 turns the leveru-41of the valve"? 36 so that the passagesof-its body 38 make the following connections: 23", 40, 33', 33, 30 and chamber K, chamber K 34, 35, 35, 39, 37 and atmosphere. The roller 48 now releases the lever 41 and air enters the chamber K of the piston18, forcin the piston 17 forward, straightening outthe toggles 12, 12 and closing the die as shown in Fi 2. This causes the circuit 54 to be close at 55, the coil 53 isQenergized and withdraws its core 52 from the recess 51 of the cam so that the handle 44 may be'tu'rned further in the direction of its arrow 45. The roller 49 at the end of the lever 47 now enters the eye of the lever 28, rotating the lever arm and the body of, the valve 22 makes the following connections when the parts are in the position shown in Fig. 6: 23', 27, 20, 20 cha1nber K, and chamber K, 21, 21, 26, 24. The position of thevalve 36 is not affected. The air inthe chamber K now pushes forward the hollow piston 18 in which the osition of the piston 17 remains unchange and the frame 9, so that the die 10, 11 isconnected with the nozzle 2 as shown in Fig. 3. The motion of the frame 9 causes the toggle levers 56, 57 to become strai htened and the lever 57 in the pair at .the le t closes the contact 8 of the circuit 7 that the coil 6 is energized and attracts its core 5 which now releases the body of the valve 4 so that it may be operated to admit air to the reservoir ough the pipe 3'. d When the casting operation has been completed the handle 44 is turned against the arrow 45. I When it has been turned through a slight angle as shown in Fig. 7 the eccentrics 58 onthe-shaft 43 raise. the toggle levers 56, 57 which is necessary as otherwise the frame 9 .could not be returned to its initial position. This also opens the contact 8' and the core 5 tends 'to return into its initial position in which it locks, the valve4 against rotation, Upon further turning of the handle 44 against the arrow 45 the position in Fig. 5 will be reached. Air now enters the chamber K and is discharged from K through the valve 22 and the hollow piston until the valve, 36 has been returned to its initial position in Fig. 4 upon further rotation of the .handle '44. Air is now supplied to thechamber K and. discharged from the chamber K in the hollow pistonthrough the valve 36, returning the piston 17 to its initial position and opening the die. The parts are now a ain in the position of Fig. 1, and ready or another operation.

Referring now to Figs. 10 to 15, these show a mechanical locking device for preventing untimely operation of the valve 4. In this device, a pawl 60 is secured on the shaft of the handle 44 which is in the axial plane of the piston rods 16 and 18. A ongitudinal slot 61 is formed in the hollow piston rod 18 and a recess 62 is formed in the solid piston rod 16 and adapted to register with the slot 61 when the die has been closed. Only when the slot and the recess register in this manner as shown in Fig. 13, the handle 44 can be turned so as to advance the frame 9 towards the injection nozzle 2. It will appear .from Figs. 11 and 12 that the handle 44 can be turned freely until the valve 36 has been operated so as to close the die, as described with reference to Figs. 4 to 7. The positions of the handle 44 are the same in Figs. 4 and 11, and 5 and 12, respectively, and. the registering of the slot 61 and the recess 62 in Fig. 13 corresponds to the withdrawal of the core 52 from the recess 51 of the cam 50 in Fig. 6. -When the slot and the recess register, it is possible to turn the handle further and to operate the valve 22, as the pawl 60 is no longer obstructed,

and this registering will occur only when the toggles 12, 12' have been fully straightened so as to close the die. In other words, the valve 22 cannot be operated before the die has been closed. When it is so closed, air will be supplied to K in the manner described above, and the frame 9 will be urged forwardly by the hollow piston 18 and intoengagement with the nozzle 2.

The mechanical means for locking the air inlet valve 4 are shown in two positions in Figs. 14 and 15. The toggle levers 56, 57 are constructed as described but in this case one of the levers 57 is provided with an arm 67 the slotted eye of which engages a rod 66 having a slotted eye 64 at its other end which engages a pin 64 on a lever 63 fulcrumed in the frame. of the machine not shown at 63. This lever cooperates with a locking pin 68 which corresponds to the core 5 in Figs. 8 and 9 and is adapted to enter a notch 69 in the valve 4 so as to lock the valve when the toggles 56, 57 are at an angle as in Fig. 14 and to release the valve when they have been straightened as in Fig. 15 and the pin die opened as described with Figs. 1 to 7. v

It will be understood from the foregoing description that. both the electrical and mechanical locking means absolutely prevent untimely operation of the inlet valve-4 so that any danger to the operator is absolutely eliminated.

It will be understood as well that I am not limited to the construction shown and described as it might be modified in various ways without departing from the spirit of my invention.

I claim;

1. Die-casting machine comprising an injection nozzle, a frame, a dieon said frame, a cylinder adapted to displace said frame with respect to said nozzle, 3. cylinder inserted in said first cylinder and adapted to control the opening and closing of said die, means for supplying fluid under pressure to said two cylinders, and means for regulating the operation of said supplying means.

2. Die-casting machine comprising an injection nozzle,-a frame, a die on said frame, a stationary cylinder comprising a hollow piston adapted to displace said frame with respect to said nozzle, :1 solid piston adapted to be displaced in said hollow piston, means operatively connecting said solid piston with said die so as to control its opening and closing means for supplying fluid under pressure to said cylinder and said hollow piston, and means for regulating the operation of said supplying means.

3. Die-casting machine comprisin an injection nozzle, a frame, a die on sai frame, a cylinder adapted to displace said frame with respect to said nozzle, a cylinder inserted in said first cylinder and adapted to control the opening and closing of said die, a supply of fluid under pressure, valves for regulatin the access of such fluid to each one of said cylinders, and a manually operated shaft for operating said valves in succession.

4. Die-casting machine comprising an injection nozzle, a frame, a die on said frame, a die comprising a. part fixed on said frame and a part movable thereon, toggle levers inserted between said movable part and said frame, means for operating said tog 1e levers so as to control said die, means or displacing said frame, toggle levers adapted to lock said frame in its final position, means for supplying fluid to said displacing and controlling means and said injection nozzle, means for regulating the fluid supply to said displacing and die controlling means, a contact in'a circuit operatively connected with said die controlling means, means in said circuit for temporarily locking said regulating means agalnst operation, a contact in a circuit operatively connected with said frame locking toggle levers, and means reference to in said circuit for temporarily-locking the injection nozzle supplying means against operation.

5. Die-casting machine comprising an injection nozzle, a frame, a die on said frame, a c linder adapted to displace said frame wit respect to said. nozzle, a cylinder insertedin said first cylinder and adapted to control the opening and closing of said die, a supply of fluid under pressure, a four-way cock connected to each cylinder and-to said supply, a manually operated shaft, a lever on said shaft adapted to cooperate with each four-way cock, and levers on said cocks ada ted to be engaged by said lever on said sha during part of-a rotation of said shaft only.-

6. Die-casting machine comprising an injection nozzle, a frame, a die on said frame, a stationary cylinder comprising a hollow piston adapted to displace said frame with respect to said nozzle, a solid piston adapted to bedisplaced in said hollow piston, a piston rod comprising a tail rod connected with said solid piston, means operatively connecting said solid piston with said die so as to control its opening and closing, means for supplying fluid under pressure to said cylinder and said hollow piston, said latter means being partl constituted by longitudinal passages de ned in said tail rod, and

displacing and die controlling means, said regulating means comprising a manually operated shaft, a cam on said shaft defining a recess, a locking bolt in an electric circuit normally entering said recess, a contact in said circuit adaptedto be closed by said die controlling toggle levers so as to withdraw said bolt from said recess when said levers have become straightened, and means operatively connected with said frame locking toggle levers for temporarily locking the injection nozzle supplying means against operation.

In testimony whereof the foregoing specification is signed.

ALBERT KAUFMANN. 

